python - python 错误退出后未执行 Bash 陷阱

Question

我有以下在 Ubuntu 12 上运行的 bash 脚本:

#!/bin/bash -e
if [[ -f ".build.lock" ]]; then
   echo "A build is already in progress by another user. Unable to continue, exiting."
   echo "   If this is a mistake, delete the '.build.lock' file to forcefully unlock"
   exit 1
else
   touch .build.lock
   echo "Build Lock Created"

   pushd ~/build-server-scripts > /dev/null

   # Execute main build script
   python3 my-build.py "$@"

   popd > /dev/null
fi

__cleanup()
{
   echo "Build Lock Removed"
   [[ -f ".build.lock" ]] && rm ".build.lock"
}

trap __cleanup EXIT

每当我从我的 python 脚本中抛出异常(大多数未处理)时，我希望 bash 脚本随后也会失败并执行 TRAP。然而，事实并非如此。我在这里缺少什么？

这是我如何处理 python(使用 python 3.2)脚本中的错误的示例:

try:
   # Do lots of other business logic here

   # 'os.setsid' needed to terminate process later for interrupts.
   process = subprocess.Popen('./ziosk-build.sh', preexec_fn=os.setsid)
   process.communicate()

except KeyboardInterrupt:
   print('\n\nSIGINT (CTRL+C?) received; stopping\n')
   try:
      os.killpg(process.pid, signal.SIGTERM)
   except NameError:
      pass

except RuntimeError as e:
   print('>>> ERROR >>>', e)
   sys.exit(1)

在上面的脚本中，我明确地处理了一些异常。当我收到键盘中断时，我想退出，调用它的 bash 脚本应该用陷阱清除构建锁。当发生任何其他运行时错误时，我也会处理并打印它以获取上下文和信息。

当然还有其他异常类型我没有明确处理，但那些目前不会导致陷阱被执行。

感谢帮助!!

Answer 1

当 Python 脚本出错时，您的 __cleanup 函数不会执行，因为脚本在到达注册处理程序的 trap __cleanup EXIT 语句之前退出。将 trap 语句和 __cleanup 函数放在脚本的顶部。

#!/bin/bash -e

__cleanup()
{
   echo "Build Lock Removed"
   [[ -f ".build.lock" ]] && rm ".build.lock"
}
trap __cleanup EXIT

if [[ -f ".build.lock" ]]; then
   echo "A build is already in progress by another user. Unable to continue, exiting."
   echo "   If this is a mistake, delete the '.build.lock' file to forcefully unlock"
   exit 1
else
   touch .build.lock
   echo "Build Lock Created"

   pushd ~/build-server-scripts > /dev/null

   # Execute main build script
   python3 my-build.py "$@"

   popd > /dev/null
fi